Objective:To discuss the effect of bone marrow mesenchymal stem cells(BMSCs)-derived exosomes(Exo)on isoproterenol(ISO)-induced myocardial fibrosis in the rats,and to clarify its mechanism.Methods:The Exo was isolated from the BMSCs and characterized by transmission electron microscope,nanoparticle tracking analysis,and Western blotting methods.Forty SD rats were divided into control group,model group,BMSCs-Exo group,and BMSCs-Exo+ferroptosis activator(Erastin)group,and there were 10 rats in each group.The myocardial fibrosis models were established by subcutaneous injection of ISO in all the rats except control group.The rats in BMSCs-Exo and BMSCs-Exo+Erastin groups were given BMSCs-Exo,and the rats in BMSCs-Exo+Erastin group were additionally injected with Erastin intraperitoneally.After 4 weeks,echocardiography was used to detect the left ventricular ejection fraction(LVEF),left ventricular fractional shortening(LVFS),left ventricular end diastolic diameter(LVEDD),and left ventricular end systolic diameter(LVESD)of the rats in various groups;HE staining was used to observe the pathomorphology of myocardium tissue of the rats in various groups;Masson staining was used to observe the fibrosis degrees of myocardium tissue of the rats in various groups;immunohistochemistry was used to detect the positive expression rates of α-smooth muscle actin(α-SMA),type Ⅰ collagen(COL-Ⅰ),and type Ⅲ collagen(COL-Ⅲ)in myocardium tissue of the rats in various groups;colorimetry was used to detect the Fe2+level in myocardium tissue of the rats in various groups;Western blotting method was used to detect the expression levels of acyl-CoA synthetase long chain family member 4(ACSL4),ferritin heavy chain 1(FTH1),glutathione peroxidase 4(GPX4),and solute carrier family 7 member 11(SLC7A11)proteins in myocardium tissue of the rats in various groups.Results:The particles isolated from BMSCs had a typical lipid bilayer structure,and most particle sizes distributed around 100 nm.High expression levels of CD63,CD9,tumor susceptibility gene 101(TSG101),and heat shock protein 70(HSP70)proteins confirmed the particles as Exo.Compared with control group,the LVEF and LVFS of the rats in model group were significantly decreased(P＜0.05),LVEDD and LVESD were increased(P＜0.05),the myocardial cell arrangement was disordered,some nuclear shrinkage and necrosis were seen,the collagen volume fraction(CVF)was significantly increased(P＜0.05),the positive expression rates of α-SMA,COL-Ⅰ,and COL-Ⅲ were significantly increased(P＜0.05),the Fe2+level in myocardium tissue was significantly increased(P＜0.05),the expression level of ACSL4 protein was significantly increased(P＜0.05),and the expression levels of FTH1,GPX4,and SLC7A11 proteins were significantly decreased(P＜0.05).Compared with model group,the LVEF and LVFS of the rats in BMSCs-Exo group were significantly increased(P＜0.05),the LVEDD and LVESD were significantly decreased(P＜0.05),the myocardial tissue damage was significantly alleviated,the CVF was significantly decreased(P＜0.05),the positive expression rates of α-SMA,COL-Ⅰ,and COL-Ⅲ were significantly decreased(P＜0.05),the Fe2+level in myocardium tissue was significantly decreased(P＜0.05),the expression level of ACSL4 protein was significantly decreased(P＜0.05),and the expression levels of FTH1,GPX4,and SLC7A11 proteins were significantly increased(P＜0.05).Compared with BMSCs-Exo group,the LVEF and LVFS of the rats in BMSCs-Exo+Erastin group were significantly decreased(P＜0.05),the LVEDD and LVESD were significantly increased(P＜0.05),the myocardial cell edema and necrosis were seen,the CVF was significantly increased(P＜0.05),the positive expression rates of α-SMA,COL-Ⅰ,and COL-Ⅲ were significantly increased(P＜0.05),the Fe2+level in myocardium tissue was significantly increased(P＜0.05),the expression level of ACSL4 protein was significantly increased(P＜0.05),and the expression levels of FTH1,GPX4,and SLC7A11 proteins were significantly decreased(P＜0.05).Conclusion:BMSC-derived Exo can improve the myocardial fibrosis in the rats induced by ISO,and its mechanism may be related to the inhibition of ferroptosis.

Objective: To analyze the effect of body mass index (BMI) on the number of lymph nodes (LNs) harvested in patients who underwent colorectal cancer resection. Methods: A retrospective analysis of 328 patients with colorectal cancer who were treated at Fujian Provincial Hospital between December 2014 and January 2017 was conducted. All patients underwent colorectal cancer resec-tion and were assigned into 2 groups:<12-LN group and≥12-LN group. Potential clinicopathological variables that might influence the number of LNs harvested were statistically analyzed. Results: Univariate analyses demonstrated that BMI (χ2=7.697, P=0.006), tumor location (χ2=7.900, P=0.048), and TNM stage (χ2=34.795, P<0.01) affected the number of LNs harvested. Logistic regression analysis re-vealed that BMI of≥25 kg/m2 and rectosigmoid location were associated with 2.557-and 1.731-fold increases in the number of LNs harvested, compared with BMI<25 kg/m2 group and other tumor locations, respectively. Conclusions: Higher BMI may decrease the number of LNs harvested in patients who underwent colorectal cancer resection and could affect the postoperative pathological stage. K

OBJECTIVE: To investigate the safety of the controllable ileostomy with pipe in view of histology. METHODS: Twenty-eight Beagle dogs undergoing controllable ileostomy with pipe were studied. The special fistula tube with balloon was placed into the hole locating at the cecal root opposing the mesenteric side, and fixed by double knot compression method. RESULTS: The fistula tube was removed 14 days after surgery, then the safety of the procedure was preliminarily evaluated by gastrointestinal radiography and anatomical observation. The small intestine tissue at the compression suture was used as the experimental segment, and the small intestine tissue at the proximal non-compression suture was used as the control segment. The histological staining and the immunohistochemical staining of S-100 protein, c-kit protein and α-smooth muscle actin(α-SMA) protein between two segment were compared, while quantitative comparison of myenteric plexus, intestinal Cajal cell(ICC) and smooth muscle cells in intestinal wall was carried out. After removal of fistula tube at 14 days postoperative, the dogs were normal in feeding and defecation. The digestive tract radiography showed that the intestine was patent without obvious stenosis and obstruction. The dogs were dissected 21 days after operation. The abdominal sinus ostium was well healed and the internal sinus was well formed. Under gross inspection, blood supply, morphology and motor function of experimental intestine segment were similar from the proximal and distal segments of control intestine. S-100 immunohistochemical staining showed that the morphology and distribution of S-100 protein positive cells and "blank area" cells in the experimental and control segments were consistent. Myenteric plexus counting showed that the experimental segment was 3.62±1.82/field and the control segment was 3.27±1.62/field, whose difference was not statistically significant(t=1.30, P=0.20). Immunohistochemical staining of c-kit showed that the distribution of c-kit positive cells in both segments was consistent. Counting of the number of ICCs in myenteric plexus revealed that experimental segment was 2.96±2.57/plexus, and control segment was 2.49±1.80/plexus without significant difference(t=1.81, P=0.07). Immunohistochemical staining of α-SMA showed that the morphology and distribution of smooth muscle cells in whole intestinal wall(muscle layer, longitudinal muscle, ring muscle) in experimental and control segments were consistent. The average absorbance(A) value of α-SMA staining in ring muscle layer was detected and quantified. The experimental segment was 0.15±0.03 and control segment was 0.14±0.04 without significant difference(t=1.16, P=0.25). CONCLUSION The technique of controllable ileostomy with pipe is safe in view of histology, which may replace the traditional protective ileostomy.
Animals ; Dogs ; Ileostomy ; methods ; standards ; Intestine, Small ; surgery ; Models, Animal ; Proto-Oncogene Proteins c-kit ; metabolism ; Treatment Outcome